Certain water heater appliances include a tank therein. Heating elements, such as gas burners, electric resistance elements, or sealed systems, heat water within the tank during operation of such water heater appliances. In particular, the heating elements generally heat water within the tank to a predetermined temperature. The predetermined temperature is generally selected such that heated water within the tank is suitable for showering, washing hands, etc.
During operation, relatively cool water flows into the tank, and the heating elements operate to heat such water to the predetermined temperature. Thus, the volume of heated water available at the predetermined temperature is generally limited to the volume of the tank. According, water heater appliances are sold in various sizes to permit consumers to select a proper tank volume and provide sufficient heated water. However, large water heater appliances with large tanks occupy large amount of space within a residence or business. In certain buildings, space is limited and/or expensive. Thus, utilizing large water heater appliances can be impractical and/or prohibitively expensive despite needing large volumes of heated water.
To provide relatively large volumes of heated water from relatively small tanks, certain water heater appliances utilize a mixing valve. The mixing valve permits water within the water heater's tank to be stored at relatively high temperatures. The mixing valve mixes such high temperature water with relatively cool water in order to bring the temperature of such water down to suitable and/or more usable temperatures. Thus, such water heater appliance can provide relatively large volumes of heated water without requiring large tanks.
Using mixing valves with water heater appliances can have drawbacks. For example, heated water from the tank can cycle through the mixing valve due to natural convection currents when the water heater appliance is not experiencing a water draw, and such water cycling can reduce an efficiency of the water heater appliance. To limit such water flow, certain water heater appliances include a check valve that blocks water flow back into the tank from the mixing valve. However, installing check valves can also have drawbacks. For example, check valves can create pockets of relatively cold water around that mixing valve. Thus, when a water draw event occurs, a slug of hot water can flow through the mixing valve before the mixing valve can suitably adjust its mixing ratio.
Accordingly, a water heater appliance having a mixing valve that includes features for restricting water flow between the mixing valve and a tank of the water heater appliance would be useful. In particular, a water heater appliance having a mixing valve that includes features for restricting water flow between the mixing valve and a tank of the water heater appliance when the water heater appliance is not experiencing a water draw would be useful.